Do I have a remote hacker in my system?

While working on a problem I am having with the installation of a firewall in my Win 2K Pro service pack 4 system, I happened across Control Panel>Administration Tools>Computer Management>shared folders>shares and saw that I have a folder called Admin$ in C:\WINNT, with a descriptive comment of "remote admin"

I have been paranoid about security ever since setting up a home based office to work for an employer 2 hrs. away, and having a conversation with one of their computer gurus who bragged about having password crackers, and the ability to set up monitoring in a system that would not be detectable by antivirus/spyware programs.

I have recently done a complete major geeks malware protocol to eliminate viruses from the list of possibilities as to why I can't install Comodo firewalls, and it came back as clean, yet I have no reason to have a remote administrator, and in fact, have shut off all of those processes.

Should I take a chill pill, or should I look into this Admin$??